Abstract:Ershiyizhan region localed in Tahe, Great Xinggan Mountains, northeastern Heilongjiang province, Early Jurassic granite, monzonite and Early Cretaceous monzonite, quartz-monzonite and so on are included. In which has discovered porphyry Cu-Au deposit, but the physical and chemical conditions of formation and the metallogenic potential of different lithologies are unclear. Based on the detailed petrographic observation of granite, monzonite, quartz-monzonite porphyry, this paper provides systematic chemical composition study on biotite and amphibole from samples of different lithologies to explore the formation conditions and the significance of petrogenesis and metallogenic . The results show that the amphibole from the Early Cretaceous monzonite, which are rich in magnesium（MgO 13.61%-14.85%）, calcium（CaO 11.21%-11.78%）, but poor in sodium（Na2O 0.80%-1.11%）and potassium（K2O 0.40%-0.54%）, belong to Mg-amphibole. The crystallization temperatures of amphiboles are 704.92℃-805.58℃, average is 761.82℃, crystallization pressures are 73.83MPa-115.93MPa , emplacement depth are 2.8km-4.4km , the oxygen fugacity of magma is ?NNO+1.63, and water content of magma are 4.45%-5.33%, average is 4.92%. All the parameters indicate that the magma crystallize at the conditions of high temperature, high oxygen fugacity, high water content and shallow emplacement. The Fe2+/（Fe2++Mg）of biotites is homogeneous , suggesting magnesia biotite. In which the type A-biotites from Early Jurassic granite and monzonite are Fe-biotite with rich in TFeO of 19.92%-22.42% and poor in MgO of 7.99%-10.46%. And the type B-biotite from Early Cretaceous monzonite and quartz-monzonite porphyry are Mg-biotite with rich in MgO of 12.38%-14.45% and TiO2 of 1.90%-2.75%, poor in TFeO of 16.64%-17.97% and Al2O3 of 15.00%-16%.79. The crystallization temperatures of A-biotites and B-biotites are 720℃-740℃ and 750℃-780℃, crystallization pressures are 202.20-443.49MPa and 158-231MPa, and emplacement depth are 6.67-14.64km and 5.24-7.24km, the oxygen fugacity are 10-15-10-16 and 10-12-10-13, in addition, The magma is mainly derived from the partial melting of the crustal material, and some of the mantle material is involved. Which indicate that the early Cretaceous monzonite and quartz-monzonite porphyry from Ershizhan intrusions formed under high temperature, high oxygen fugacity and water content, shallow emplacement, furthermore the magma are the fusion of crust and mantle material, with huge potential of forming great porphyry Cu-Au deposit. The early Jurassic granite and monzonite from Ershiyizhan intrusions are formed under high temperature, relatively lower oxygen fugacity, but deep emplacement and the magma are from crust, so, without the conditions of forming a porphyry Cu-Au deposit.